Empathy, autism and the extreme female brain

Human cognition can be conceptualized as an axis whereby males tend toward relative strengths in mechanistic ('things' thinking) cognition and females tend toward relative strengths in mentalistic ('people'-thinking) cognition. Psychiatric conditions are hypothesized to reflect the extreme ends of this axis, with over-developed social cognition underlying the psychotic-affective spectrum in contrast to under-developed social cognition characterizing the autism spectrum. Consistent with this hypothesis, I found a diametric relationship between autistic and schizotypal features based on questionnaire data drawn from a large non-clinical sample of undergraduates. I also conducted two literature reviews asking: 1) Is mentalistic cognition enhanced in borderline personality disorder (BPD)? and 2) are BPD and depression associated with extreme female phenotypes? Both conditions involved elevated mentalistic cognition, a female-bias in their prevalence, and associations with female-typical hormonal profiles. These findings provide evidence that psychological variation is organized along an axis shaped by sex differences and that extreme expressions of evolved cognitive systems mediate a suite of psychiatric conditions.